Creosote-impregnated Waste Materials - PSL1

1.0 Introduction

The Canadian Environmental Protection Act (CEPA) requires the Minister of the Environment and the Minister of Health to prepare and publish a Priority Substances List that identifies substances, including chemicals, groups of chemicals, effluents, and wastes that may be harmful to the environment or constitute a danger to human health. The Act also requires both Ministers to assess these substances and determine whether they are "toxic" as defined under Section 11 which states:

"...a substance is toxic if it is entering or may enter the environment in a quantity or concentration, or under conditions

1. having or that may have an immediate or long-term harmful effect on the environment;
   
   
2. constituting or that may constitute a danger to the environment on which human life depends; or
   
   
3. constituting or that may constitute a danger in Canada to human life or health."

Substances that are assessed as "toxic" according to Section 11 may be placed on Schedule I of the Act. Consideration can then be given to developing regulations, guidelines, or codes of practice to control any aspect of these substances' life cycle, from the research and development stage, through manufacture, use, storage, transport, and ultimate disposal.

Use of creosote as a heavy-duty wood preservative in Canada is subject to control under the Pest Control Products Act (PCPA) which is administered by Agriculture Canada. This control does not extend to the disposal of waste products arising from the use of this substance or for the operating practices at creosote-treating facilities. The substance creosote-impregnated waste materials (CIWM) was added to the Priority Substances List under CEPA because of concerns about the potential for environmental contamination from waste materials generated at creosote wood-treatment facilities and from the replacement of creosote-treated wood products.

Creosote-impregnated waste materials are interpreted in this assessment to include:

• Creosote waste products: materials treated with creosote that have since been removed from service and are awaiting disposal (used railway ties, utility poles, etc.); and
  
  
• Creosote-contaminated sites: creosote-contaminated areas or materials resulting from the application, manufacture, storage, transportation, or spillage of creosote.

The assessment of whether the substance creosote-impregnated waste materials is "toxic", as defined under Section 11 of CEPA, was based on the determination of whether waste creosote or its component compounds enter or are likely to enter the Canadian environment in a concentration or quantities or under conditions that could lead to exposure of humans or other biota at levels that could cause adverse effects.

The potential effects of waste creosote from CIWM on human health have not been widely studied. There is some information available on the effects of polycyclic aromatic hydrocarbons (PAHs) in experimental animals and humans. Polycyclic aromatic hydrocarbons are the major group of compounds found in waste creosote. A preliminary literature survey did not identify sufficient data to assess the degree of human exposure to PAHs from CIWM. Polycylic aromatic hydrocarbons are being addressed in a separate Assessment Report so their potential effects on human health will not be discussed herein. No information was identified to indicate that CIWM affects the environment upon which human life depends. Therefore, detailed consideration of whether the substance CIWM is "toxic" as defined under Paragraphs 11(b) and 11(c) of the Act is not included in this assessment.

Data relevant to the assessment of the entry, environmental exposure, and environmental effects of waste creosote were obtained from review documents, reference books, and papers in scientific journals identified through searches of electronic databases up to 1991. These databases included: BIOSIS Previews, Pollution Abstracts, ENVIROLINE, ENVIROFATE, Environment Canada Departmental Library Catalogue (ELIAS), International Register of Potentially Toxic Chemicals (IRPTC), Chemical Evaluation Search and Retrieval System (CESARS), the United States Environmental Protection Agency's (U.S. EPA) Risk Reduction Engineering Laboratory (RREL) Treatability database, Register of Toxic Effects of Chemical Substances (RTECS), Chemical Hazard Response Information System (CHRIS), National Institute of Occupational Safety and Health Technical Information Center (NIOSHTIC), and National Technical Information Service (NTIS). Site assessment reports prepared by governments and the wood preservation industry were used in this assessment. In addition, a study was undertaken under contract to gather trade information on the usage of creosote in Canada from the Canadian wood preservation industry, Agriculture Canada, Statistics Canada, Public Works Canada, utility companies, and other corporate users of creosoted products.

Although much of the research on CIWM has been conducted outside Canada, available Canadian data on sources, fate, levels, and effects of CIWM on the Canadian environment were emphasized. All original studies that form the basis for determining whether CIWM are "toxic" as defined under Section 11 of CEPA have been critically evaluated by the following Environment Canada staff:

A. Beckett
M. Constable
E. Gordy
T. Lambert
B. Munson, Task Group Leader

Creosote-impregnated waste materials were characterized by the following individuals from Environment Canada: J. Sproull, E. Gordy, N. Gurprasad, and G. Atkinson.

In this report, a Synopsis is presented which will appear in the Canada Gazette. A summary of technical information that is critical to the assessment is presented in Section 2.0. The assessment of whether CIWM are "toxic" as defined under the Canadian Environmental Protection Act is presented in Section 3.0. A Supporting Document that discusses the technical information in greater detail has also been prepared and is available upon request.

As part of the review and approvals process established by Environment Canada for their contributions to Priority Substance assessment reports, this Assessment Report and the Supporting Document were reviewed by a number of experts from Environment Canada, G. Brudermann (wood preservation consultant), and J. Butala (School of Pharmacy, Duquesne University). The final Assessment Report was reviewed and approved by the Environment Canada/Health Canada CEPA Management Committee.

Copies of this Assessment Report and the unpublished Supporting Document are available upon request from: